Medical grafting connectors and fasteners

ABSTRACT

A body tissue graft for use in a patient includes a frame structure made of a first elastic material, a covering of a second elastic material on the frame structure, the covering substantially filling openings in the frame structure, and a connector connected to the frame structure. Projections are secured to the connector structure. The projections facilitate attachment of the tubular graft in a patient by securing the graft to the body tissue with which the graft is employed. The connector selectively circumferentially expands and the projections selectively circumferentially expand. This may be done using an inflatable balloon to circumferentially expand the projections. A restraining member may be provided to restrain the projections in a cone shape so that an end of the graft may be used to open an aperture through a side wall of existing body organ tubing and a portion of the projections may enter the aperture.

This is a continuation of application Ser. No. 11/060,520, filed Feb.17, 2005, now U.S. Pat. No. 7,211,095, which is a continuation ofapplication Ser. No. 10/188,699, filed Jul. 2, 2002, now abandoned,which is a continuation of application Ser. No. 09/406,575, filed Sep.24, 1999, now abandoned, which is a continuation of application Ser. No.08/839,199, filed Apr. 23, 1997, now U.S. Pat. No. 6,036,702, all ofwhich are hereby incorporated by reference herein in their entireties.

BACKGROUND OF THE INVENTION

This invention relates to medical grafting methods and apparatus, andmore particularly to methods and apparatus for connecting or fasteningtubular bypass grafts.

An example of the possible uses of the invention is a minimally invasivecardiac bypass procedure. This example will be considered in detail, butit will be understood that various aspects of the invention have manyother possible uses.

Several procedures are known for revascularizing the human heart inorder to treat a patient with one or more occluded coronary arteries.The earliest of these procedures to be developed involves exposing theheart by means of a midline sternotomy. Following surgical exposure ofthe heart, the patient's aorta and vena cava are connected to aheart/lung machine to sustain vital functions during the procedure. Thebeating of the heart is stopped to facilitate performance of theprocedure. Typically, a suitable blood vessel such as a length of thepatient's saphenous (leg) vein is harvested for use as a graft. Thegraft is used to create a new, uninterrupted channel between a bloodsource, such as the aorta, and the occluded coronary artery or arteriesdownstream from the arterial occlusion or occlusions. A variation of theabove procedure involves relocating a mammary artery of the patient to acoronary artery.

Although the above-described sternotomy procedures are increasinglysuccessful, the high degree of invasiveness of these procedures and therequirement of these procedures for general anesthesia are significantdisadvantages. Indeed, these disadvantages preclude use of sternotomyprocedures on many patients.

More recently, less invasive procedures have been developed forrevascularizing the heart. An example of these procedures is known asthoracostomy, which involves surgical creation of ports in the patient'schest to obtain access to the thoracic cavity. Specially designedinstruments are inserted through the ports to allow the surgeon torevascularize the heart without the trauma of a midline sternotomy.Drugs may be administered to the patient to slow the heart during theprocedure. Some thoracostomy procedures involve relocating a mammaryartery to a coronary artery to provide a bypass around an occlusion inthe coronary artery.

Thoracostomy bypass procedures are less traumatic than sternotomy bypassprocedures, but they are still too traumatic for some patients. Also,the number of required bypasses may exceed the number of mammaryarteries, thereby rendering thoracostomy procedures inadequate to fullytreat many patients.

Another technique for revascularizing the human heart involves gainingaccess to the thoracic cavity by making incisions between the patient'sribs. This procedure is known as thoracotomy. It is also substantiallyless traumatic than midline sternotomy, but it is still too traumaticfor some patients.

In view of the foregoing, even less traumatic approaches have beendeveloped for revascularizing a patient, as described in Goldsteen etal. U.S. patent application Ser. No. 08/745,618, filed Nov. 7, 1996, andhereby incorporated by reference herein in its entirety. With suchapproaches, a graft (e.g., of saphenous vein) can be delivered to anoperative site in the patient through the patient's existing arteriesand veins. The graft is typically inserted between two attachment sitesin the patient's existing body organs (e.g., between a site along thepatient's aorta and a site along the coronary artery downstream from acoronary artery occlusion).

Thus the above-mentioned Goldsteen et al. reference shows, among otherthings, methods and apparatus for installing tubular bypass graftsintralumenally. The Goldsteen et al. reference shows methods andapparatus in which each end of the graft site is approached separatelyand intralumenally, penetrated, and then a longitudinal structure (e.g.,element 150 in the Goldsteen et al. reference) is established betweenthe ends of the graft site. This longitudinal structure may extendintralumenally all the way out of the patient's body from both ends ofthe graft site. The graft is fed into the patient's body intralumenallyalong the longitudinal structure until it is in the desired positionextending from one end of the graft site to the other. Each end of thegraft is then secured at a respective end of the graft site and thelongitudinal structure is withdrawn from the patient.

Tubular artificial grafts are needed in various medical procedures. Forexample, such grafts may be needed to replace diseased or damagedsections of natural tubular body tissue such as in the circulatorysystem, the urinary tract, etc. Or such grafts may be needed to make newconnections in natural tubular body tissue systems such as bypass orshunt connections in the circulatory system. In general, an artificialtubular graft may be needed as either a temporary or permanentinstallation.

Important considerations regarding the use of artificial grafts includeease of use, time required for installation, secureness of installation,and performance after installation. Improvements are constantly soughtin all of these areas.

It is therefore an object of this invention to provide improved grafts.

It is therefore a further object of this invention to provide improvedmethods and apparatus for the connection of grafts, whether natural orartificial.

It is therefore a further object of the invention to provide improvedgraft structures for use in the repair, replacement, or supplementing ofnatural body organ structures or tissues, and to provide methods andapparatus for fastening or connecting such graft structures.

It is therefore a further object of this invention to provide improvedmethods and apparatus for installing medical grafts, whether natural orartificial.

SUMMARY OF THE INVENTION

This and other objects of the invention are accomplished in accordancewith the principles of the invention by providing apparatus for use as abody tissue graft and methods for securing the graft in a patientcomprising a frame structure made of a first elastic material, acovering of a second elastic material on the frame structure, thecovering substantially filling openings in the frame structure, and aconnector connected to the frame structure. Projections are secured tothe connector structure. The projections facilitate attachment of thetubular graft in a patient by securing the graft to the body tissue withwhich the graft is employed. The connector selectively circumferentiallyexpands and the projections selectively circumferentially expand. Thismay be done using an inflatable balloon to circumferentially expand theprojections and the connector. A restraining member may be provided torestrain the projections in a cone shape so that an end of the graft maybe used to open an aperture through a side wall of existing body organtubing and a portion of the projections may enter the aperture. Theconnector structures of this invention may be used with artificialgrafts having any construction (i.e., other than the frame-and-coveringconstruction mentioned above), and they may also be used with naturalbody tissue grafts.

Further features of the invention, its nature, and various advantageswill be more apparent from the accompanying drawings and the followingdetailed description of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified longitudinal sectional view showing a portion ofan illustrative procedure and related apparatus in accordance with thisinvention.

FIG. 2 is a simplified longitudinal sectional view showing a portion ofa more particular illustrative procedure and related apparatus inaccordance with the invention.

FIG. 3 is a simplified longitudinal sectional view showing anillustrative embodiment of a portion of the FIG. 2 apparatus in moredetail.

FIG. 4 is a view similar to FIG. 2 showing a later stage in theillustrative procedure depicted in part by FIG. 2, together with relatedapparatus, all in accordance with this invention.

FIG. 5 shows an even later stage in the illustrative procedure depictedin part by FIG. 4, together with related apparatus, all in accordancewith this invention.

FIG. 6 is a view similar to FIG. 4 showing a still later stage in theillustrative procedure depicted in part by FIG. 5.

FIG. 7 is a simplified longitudinal sectional view of an illustrativeembodiment of a portion of an illustrative apparatus in accordance withthis invention.

FIG. 8 is a simplified elevational view of an illustrative embodiment ofone component of the FIG. 7 apparatus.

FIG. 9 is a simplified longitudinal sectional view of an illustrativeembodiment of another portion of the FIG. 7 apparatus.

FIG. 10 is a view similar to a portion of FIG. 6 showing an even laterstage in the illustrative procedure depicted in part by FIG. 6.

FIG. 11 is a view similar to FIG. 10 showing a still later stage in theFIG. 10 procedure.

FIG. 12 is a view similar to FIG. 11 showing an even later stage in theFIG. 11 procedure.

FIG. 13 is a view similar to another portion of FIG. 6 showing a stilllater stage in the FIG. 12 procedure.

FIG. 14 is a view similar to FIG. 13 showing an even later stage in theFIG. 13 procedure.

FIG. 14 a is a view similar to FIG. 14 showing a still later stage inthe FIG. 14 procedure.

FIG. 14 b is a view similar to FIG. 14 a showing an even later stage inthe FIG. 14 a procedure.

FIG. 15 is a view similar to FIG. 14 b showing a still later stage inthe FIG. 14 b procedure.

FIG. 16 is a view similar to FIG. 15 showing an even later stage in theFIG. 15 procedure.

FIG. 17 is a simplified longitudinal sectional view of an illustrativeembodiment of a portion of more apparatus in accordance with thisinvention.

FIG. 18 is a view similar to FIG. 12 showing a later stage in the FIG.16 procedure.

FIG. 19 is a view similar to FIG. 18 showing a still later stage in theFIG. 18 procedure.

FIG. 20 is a view similar to FIG. 16 showing an even later stage in theFIG. 19 procedure.

FIG. 21 is a view similar to FIG. 20 showing a still later stage in theFIG. 20 procedure.

FIG. 22 is a view similar to FIG. 21 showing an even later stage in theFIG. 21 procedure.

FIG. 23 is a view similar to FIG. 6 showing the end result of theprocedure depicted in part by FIG. 22.

FIG. 24 is a simplified longitudinal sectional view showing an endresult similar to FIG. 23 but in a different context.

FIG. 25 is a simplified elevational view (partly in section) showinganother possible alternative construction of portions of the FIG. 7apparatus.

FIG. 26 is a simplified longitudinal sectional view of the FIG. 25apparatus in another operating condition.

FIG. 26 a is a simplified elevational view (partly in section) showinganother possible alternative construction of portions of the FIG. 7apparatus.

FIG. 26 b is a simplified elevational view of an illustrative embodimentof one component of the apparatus shown in FIG. 26 a.

FIG. 27 is a simplified end view of an illustrative embodiment of acomponent of the graft shown in FIGS. 25 and 26.

FIG. 28 is an elevational view of a structure that can be used to make aparticular embodiment of the apparatus portion shown in FIG. 27.

FIG. 29 is a simplified elevational view of a subsequent condition ofthe FIG. 28 structure during fabrication.

FIG. 29 a is a simplified enlargement of a portion of FIG. 29 with othercomponents added.

FIG. 30 is a simplified longitudinal sectional view showing anotherpossible alternative construction of portions of the apparatus shown inFIG. 7.

FIG. 30 a is a simplified longitudinal sectional view showing stillanother possible alternative construction of portions of the apparatusshown in FIG. 7.

FIG. 31 is a simplified longitudinal sectional view showing yet anotherpossible alternative construction of portions of the apparatus shown inFIG. 7.

FIG. 32 is a simplified longitudinal sectional view showing stillanother possible alternative construction of portions of the apparatusshown in FIG. 7.

FIG. 33 is a view similar to FIG. 13 showing an alternative illustrativeembodiment of certain components.

FIG. 34 is a view similar to a portion of FIG. 16 for the alternativeembodiment shown in FIG. 33.

FIG. 34 a is another view similar to FIG. 34 showing another alternativeillustrative embodiment of the invention.

FIG. 34 b is an elevational view taken from the right in FIG. 34 a.

FIG. 35 is a simplified elevational view of apparatus which can be usedas an alternative to certain apparatus components shown in FIG. 7.

FIG. 36 is a view similar to a composite of FIGS. 7 and 9 showinganother alternative illustrative embodiment of certain aspects of theinvention.

FIG. 37 is a simplified elevational view showing another illustrativeembodiment of an artificial graft constructed in accordance with theinvention.

FIG. 38 is another view similar to FIG. 37 showing another operatingcondition of the FIG. 37 graft.

FIG. 39 is another view similar to FIG. 37 showing the graft beinginstalled in tubular body tissue.

FIG. 40 is another view similar to FIG. 39 showing a later stage in theinstallation of the graft.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Because the present invention has a number of different applications,each of which may warrant some modifications of such parameters asinstrument size and shape, it is believed best to describe certainaspects of the invention with reference to relatively generic schematicdrawings. To keep the discussion from becoming too abstract, however,and as an aid to better comprehension and appreciation of the invention,references will frequently be made to specific uses of the invention.Most often these references will be to use of the invention to provide abypass around an occlusion or obstruction (generically referred to as anarrowing) in a patient's coronary artery, and in particular a bypassfrom the aorta to a point along the coronary artery which is downstreamfrom the coronary artery narrowing. It is emphasized again, however,that this is only one of many possible applications of the invention.

Assuming that the invention is to be used to provide a bypass from theaorta around a coronary artery narrowing, the procedure may begin byinserting an elongated instrument into the patient's circulatory systemso that a distal portion of the instrument extends through the coronaryartery narrowing to the vicinity of the point along the artery at whichit is desired to make the bypass connection. This is illustrated by FIG.1, which shows elongated instrument 100 entering the patient'scirculatory system 10 at a remote location 12 and passing coaxiallyalong vessels in the circulatory system until its distal end portion 104passes through narrowing 22 in coronary artery 20 and reaches thedownstream portion 24 of the artery to which it is desired to make abypass connection. For example, the entry location 12 of instrument 100may be a femoral (leg) artery of the patient, a brachial artery of thepatient, or any other suitable entry point. It will be appreciated,however, that entry point 12 is typically remote from the location atwhich the bypass is to be provided, and that control of instrument 100throughout its use is from the proximal portion 102 that is outside thepatient at all times.

For the illustrative procedure being discussed, FIG. 2 shows a preferredembodiment of instrument 100 in more detail. As shown in FIG. 2,instrument 100 may include a catheter tube 110 which is inserted (fromlocation 12 in FIG. 1) via the patient's aorta 30 to the ostium ofcoronary artery 20. Another tubular structure 120 is then extended fromthe distal end of catheter 110, through narrowing 22 to location 24.

An illustrative construction of tubular structure 120 is shown in moredetail in FIG. 3. There it will be seen that structure 120 may have twolumens 130 and 140. Near the distal end of structure 120, lumen 130communicates with the interior of an inflatable balloon 132 on one sideof structure 120, while lumen 140 opens out to the opposite side ofstructure 120. Lumen 140 contains a longitudinal structure 150 which maybe a stylet wire with a sharpened distal tip 152. Structure 120 may beprovided with a distal spring tip 122 to help guide the distal end ofstructure 120 along coronary artery 20 and through narrowing 22. Asafety ribbon 123 (e.g., of the same material as tip 122) may beconnected at its proximal end to the distal end of member 120 and at itsdistal end to the distal end of tip 122 to improve the performance oftip 122 and to help prevent separation of any portion of tip 122 fromstructure 120 in the event of damage to tip 122. Structure 120 may haveradiologic (e.g., radio-opaque or fluoroscopically viewable) markers 124at suitable locations to help the physician place the structure wheredesired in the patient's body. Catheter 110 may also have radiologicmarkers 112 for similar use. Balloon 132 is initially deflated.Longitudinal structure 150 is initially retracted within lumen 140.However, the distal portion of lumen 140 is shaped (as indicated at 142in FIG. 2) to help guide the distal tip 152 of structure 150 out to theside of structure 120 when structure 150 is pushed distally relative tostructure 120. This is discussed in more detail below. As earlierdescription suggests, each of components 110, 120, and 150 is separatelycontrollable from outside the patient, generally indicated as region 102in FIG. 1.

After instrument 100 is positioned as shown in FIGS. 1 and 2, a secondelongated instrument 200 is similarly introduced into the patient'scirculatory system 10. For example, instrument 200 may enter the patientvia a femoral artery, a brachial artery, or any other suitable location,which again is typically remote from the bypass site. If one femoralartery is used to receive instrument 100, the other femoral artery maybe used to receive instrument 200. Or the same femoral artery may beused to receive both instruments. Or any other combination of entrypoints may be used for the two instruments. Instrument 200 is inserteduntil its distal end is adjacent to the point 34 in the circulatorysystem which it is desired to connect to point 24 via a bypass. This isillustrated in FIG. 4 where the distal end of instrument 200 is shown atlocation 34 in aorta 30. The particular location 34 chosen in FIG. 4 isonly illustrative, and any other location along aorta 30 may be selectedinstead. Radiologic markers 206 may be provided on the distal portion ofinstrument 200 to help the physician position the instrument wheredesired. Note that FIG. 4 shows portions of instruments 100 and 200 sideby side in aorta 30.

The next step in the illustrative procedure being described ispreferably to deploy a snare loop 354 (FIG. 5) from the distal end 204of instrument 200 through the aorta wall to a location outside thecoronary artery wall adjacent coronary artery portion 24. This isexplained in more detail in the above-mentioned Goldsteen et al.reference. (Alternatively, this step could be performed somewhat later.)Then stylet wire 150 is moved in the distal direction so that its distaltip 152 passes through the wall of the coronary artery. As was mentionedearlier, the distal end of the stylet wire lumen in tube 120 is shapedto help guide stylet wire 150 through the coronary artery wall.

Once wire 150 is through snare loop 354, snare sheath or lumen 340 ismoved distally relative to the snare loop as shown in FIG. 5. Thiscauses snare loop 354 to close down on wire 150. Snare sheath or lumen340 also tends to trap the distal portion of wire 150 and to fold thatwire portion back on itself inside sheath or lumen 340. The longitudinalstructures 150 and 350 are securely interengaged inside snare sheath orlumen 340. The next step is to pull snare wire 352 in the proximaldirection all the way out of the patient. Because of the interengagementbetween wires 150 and 352, withdrawing wire 352 pulls as much additionalwire 150 into the patient from external location 102 (FIG. 1). When wire352 has been completely removed from the patient, there is then onecontinuous wire 150 from outside the patient at 102, through thepatient, to outside the patient again. Wire 150 can now be moved ineither longitudinal direction through the patient. This wire or anotherwire could be used to help pull various apparatus into the patient viathe tube or tubes through which the wire passes.

After one continuous wire 150 has been established through the patientas described above, the other snare components such as 340 may bewithdrawn from the patient by pulling them proximally out of catheter210. The condition of the apparatus inside the patient is now as shownin FIG. 6. Note that the presence of fixed outlets for the wire from thedistal portion of tube 120 and the distal end of catheter 210 preventswire 150 from cutting tissues 20 and 30 when the wire is pulled ineither longitudinal direction. The portion of wire 150 extending throughthe interior of the patient between elements 120 and 210 may haveradiologic markers 154 equally spaced along its length. These can beviewed radiologically by the physician to determine the distance betweenregions 24 and 34 via wire 150. This helps the physician select thecorrect length of graft needed between regions 24 and 34.

The next phase of the illustrative procedure being described is toinstall a new length of tubing or graft between regions 24 and 34. Thenew length of tubing may be either an artificial graft, natural bodyorgan tubing harvested from the patient's body, or a combination ofartificial and natural tubing (e.g., natural tubing coaxially insideartificial tubing). In the following discussion it is assumed that thenew tubing is to be natural tubing (e.g., a length of the patient'ssaphenous vein that has been harvested for this purpose) inside anartificial conduit. When such a combination of natural and artificialconduits is used, both conduits can be delivered and installedsimultaneously, or the outer artificial conduit can be delivered andinstalled first, and then the inner natural conduit can be delivered andinstalled. The following discussion initially assumes that the lattertechnique is employed.

An illustrative embodiment of an artificial graft 430 is shown in FIG.8. Although any suitable construction can be used for the main portionof graft 430, a particularly preferred construction is shown anddescribed in the above-mentioned Goldsteen et al. reference. Forexample, this graft construction may include a tubular mesh framework432 of nitinol covered with silicone 434 to substantially fill in theinterstices in the framework. Additional details, features, andalternatives regarding this type of graft construction will be found inthe above-mentioned Goldsteen et al. reference, and in PCT publicationWO98/19632, which is also hereby incorporated by reference herein in itsentirety. Grafts having this type of construction are extremely elasticand they can be radically deformed without damage or permanent change inshape. For example, a graft of this construction can be stretched to asmall fraction of its original diameter, and it thereafter returns byitself to its original size and shape without damage or permanentdeformation of any kind. Grafts of this type can be made with anydesired porosity (e.g., through the silicone). For use in thecirculatory system, they can also be made so that they pulse in responseto pressure pulses in the blood flowing through them, very much like thepulsation of natural blood vessels. This can be important todiscouraging the formation of clots in the graft.

In accordance with the above-stated assumptions, the next step in theprocedure is to use catheter 210 and wire 150 to deliver an artificialconduit such as graft 430 so that it extends between regions 24 and 34.The distal portion of an illustrative assembly 400 for doing this isshown in FIG. 7. As shown in FIG. 7 assembly 400 includes a threaded,conical, distal tip 412 mounted on a tubular member 410 (e.g., metalhypotube) through which wire 150 can freely pass. It should be mentionedhere that in this embodiment tip 412 is selectively collapsible tofacilitate its withdrawal from the patient after it has served itspurpose. Another tubular member 420 is disposed concentrically aroundtubular member 410. An inflatable balloon 422 is mounted on the distalend of tubular member 420. Tubular member 420 includes an axiallyextending lumen (not shown in FIG. 7) for use in selectively inflatingand deflating balloon 422. Balloon 422 is shown deflated in FIG. 7.

Coaxially around tubular member 420 is artificial graft conduit 430. Ashas been mentioned, an illustrative embodiment of a suitable graftconduit 430 is shown in FIG. 8 and includes a tube formed of a frame 432of a first highly elastic material (such as nitinol) with a covering 434of a second highly elastic material (e.g., a rubber-like material suchas silicone) substantially filling the apertures in the frame. At itsdistal end, extensions of frame 432 are flared out to form resilientstruts 436. The struts 436 may have hooks and/or barbs disposed thereon.Near the proximal end of conduit 430 two axially spaced resilient flaps438 a and 438 b with prongs 439 are provided.

In assembly 400 (see again FIG. 7, and also FIG. 9), struts 436 andflaps 438 are compressed radially inwardly and confined within conduitdelivery tube 440, which coaxially surrounds conduit 430. Indeed,conduit 430 may be somewhat circumferentially compressed by tube 440.

The portion of assembly 440 at which the proximal end of conduit 430 islocated is shown in FIG. 9. There it will be seen how flaps 438 areconfined within conduit delivery tube 440. FIG. 9 also shows how tubes410, 420, and 440 extend proximally (to the right as viewed in FIG. 9)from the proximal end of conduit 430 so that the physician can remotelycontrol the distal portion of assembly 400 from outside the patient.

To install artificial graft conduit 430 in the patient between regions24 and 34, assembly 400 is fed into the patient along wire 150 throughcatheter 210. When tip 412 reaches coronary artery portion 24, tip 412is threaded into and through the coronary artery wall by rotating tube410 and therefore tip 412. (Tube 120 may be pulled back slightly at thistime to make sure that it does not obstruct tip 412.) The passage of tip412 through the coronary artery wall opens up the aperture in that wall.After tip 412 passes through the artery wall, that wall seals itselfagainst the outside of the distal portion of conduit delivery tube 440as shown in FIG. 10.

The next step is to push tube 410 and tip 412 distally relative todelivery tube 440, which is held stationary. Conduit 430 is initiallymoved distally with components 410 and 412. This may be done byinflating balloon 422 so that it engages conduit 430, and then movingtube 420 distally with components 410 and 412. Distal motion of conduit430 moves struts 436 beyond the distal end of delivery tube 440, therebyallowing the struts 436 to spring out inside coronary artery 20 as shownin FIG. 11. This prevents the distal end of conduit 430 from beingpulled proximally out of the coronary artery. If balloon 422 wasinflated during this phase of the procedure, it may be deflated beforebeginning the next phase.

The next step is to pull delivery tube 440 back slightly so that it iswithdrawn from coronary artery 20. Then tube 420 is moved distally sothat balloon 422 is radially inside the annulus of struts 436. Balloon442 is then inflated to ensure that struts 436 (and barbs and/or hooksif provided) are firmly set in coronary artery 20. Conditions are now asshown in FIG. 12. Cross sections of balloon 422 may be L-shaped wheninflated (one leg of the L extending parallel to the longitudinal axisof conduit 430, and the other leg of the L extending radially outwardfrom that longitudinal axis immediately distal of struts 436). This mayfurther help to ensure that struts 436 fully engage the wall of coronaryartery 20.

The next step is to deflate balloon 422. Then delivery tube 440 iswithdrawn proximally until flap 438 a (but not flap 438 b) is distal ofthe distal end of the delivery tube. This allows flap 438 a to springradially out as shown in FIG. 13. Tube 420 is then withdrawn untilballoon 422 is just distal of flap 438 a. Then balloon 422 is inflated,producing the condition shown in FIG. 13.

The next steps are (1) to deflate distal balloon 214, (2) to proximallywithdraw catheter 210 a short way, (3) to proximally withdraw tube 420to press flap 438 a against the outer surface of the aorta wall, and (4)to proximally withdraw delivery tube 440 by the amount required to allowflap 438 b to spring out against the interior of catheter 210, all asshown in FIG. 14. As a result of the above-described proximal withdrawalof tube 420, the prongs 439 on flap 438 a are urged to enter the aortawall tissue to help maintain engagement between flap 438 a and the wallof the aorta. Inflated balloon 422 helps to set prongs 439 in the tissuewhen tube 420 is tugged proximally.

The next step is to insert the distal portion of delivery tube 440 intothe proximal end of conduit 430 as shown in FIG. 14 a. The distal end ofconduit 430 may be inserted all the way to the proximal end of balloon422 (see FIG. 15 for a depiction of this). A purpose of this step is tosubsequently help control the rate at which blood is allowed to begin toflow through conduit 430.

The next step is to proximally withdraw catheter 210 by the amountrequired to release flap 438 b to spring out against the interior of thewall of aorta 30 as shown in FIG. 14 b. Catheter 210 may be subsequentlypushed back against flap 438 b as shown in FIG. 15 to help securelyengage that flap against the aorta wall.

Artificial graft conduit 430 is now fully established between aortaregion 34 and coronary artery region 24. The next steps are therefore todeflate balloon 422 and proximally withdraw tube 420, to collapse tip412 and proximally withdraw tube 410, and to proximally withdrawdelivery tube 440. The proximal end of conduit 430 is now as shown inFIG. 16. As possible alternatives to what is shown in FIG. 16, thedistal end of catheter 210 could be left pressed up against proximalflap 438 b and/or the distal portion of delivery tube 440 could be leftinside the proximal portion of conduit 430. If the latter possibility isemployed, then delivery of the natural graft conduit (described below)can be through tube 440.

As has been mentioned, the illustrative procedure being describedassumes that natural body conduit (e.g. a length of the patient'ssaphenous vein that has been harvested for this purpose) is installedinside artificial conduit 430 after installation of the latter conduit.An illustrative assembly 500 for delivering a length of natural bodyconduit to installed conduit 430 is shown in FIG. 17.

As shown in FIG. 17, assembly 500 includes a tube 510 disposed aroundwire 150 so that tube 510 is freely movable in either direction alongwire 150. Tube 510 has an inflatable annular balloon 512 a near itsdistal end and another inflatable annular balloon 512 b spaced in theproximal direction from balloon 512 a. Tube 510 includes separateinflation lumens (not shown) for each of balloons 512 so that theballoons can be separately inflated and deflated. An annular collarstructure or ring 520 a is disposed concentrically around balloon 512 a,and a similar annular collar structure or ring 520 b is disposedconcentrically around balloon 512 b. Balloons 512 may be partlyinflated. Each of rings 520 may have radially outwardly extending prongs522. The rings 520 may alternatively or additionally be fluted orprovided with raised portions (alternatives that are discussed below(e.g., in connection with FIGS. 27-29 a and 36)). A length of naturalbody conduit 530 (e.g., saphenous vein as mentioned earlier) extendsfrom ring 520 a to ring 520 b around the intervening portion of tube510. Prongs 522 may extend through the portions of conduit 530 thataxially overlap rings 520. A delivery tube 540 is disposed aroundconduit 530. In use, tubes 510 and 540 extend proximally (to the rightas viewed in FIG. 17) out of the patient to permit the physician toremotely control the distal portion of assembly 500.

Instead of prongs 522, the rings 520 may be provided with fluted orraised structures that grip the graft conduit 430. Instead of balloons512 being both on the same tube 510, balloon 512 a may be on arelatively small first tube, while balloon 512 b is on a larger secondtube that concentrically surrounds the proximal portion of the firsttube. The first and second tubes are axially movable relative to oneanother, thereby allowing the distance between balloons 512 to beadjusted for grafts 530 of different lengths. An illustrative apparatusof this kind is shown in Goldsteen et al. U.S. patent application Ser.No. 08/839,298, filed Apr. 17, 1997, which is hereby incorporated byreference herein.

Assembly 500 is employed by placing it on wire 150 leading into catheter210. Assembly 500 is then advanced distally along wire 150 throughcatheter 210 and then into conduit 430 until the distal end of conduit530 is adjacent the distal end of conduit 430 and the proximal end ofconduit 530 is adjacent the proximal end of conduit 430. The conditionof the apparatus at the distal end of assembly 500 is now as shown inFIG. 18. The condition of the apparatus at the proximal end of conduit530 is as shown in FIG. 20.

The next step is to proximally withdraw delivery tube 540 so that thedistal portion of conduit 530 and distal ring 520 a are no longer insidethe distal portion of delivery tube 540. Then distal balloon 512 a isinflated to circumferentially expand ring 520 a and to set prongs 522through conduit 530 into the surrounding portion of conduit 430 andcoronary artery wall portion 24. This provides a completed anastomosisof the distal end of conduit 530 to coronary artery 20. FIG. 19 showsthe condition of the apparatus at this stage in the procedure.

The next step is to continue to proximally withdraw delivery tube 540until the proximal end of conduit 530 and proximal ring 520 b are nolonger inside tube 540 (see FIG. 21). Then proximal balloon 512 b isinflated to circumferentially expand ring 520 b and thereby set prongs522 through conduit 530 into the surrounding portion of conduit 430 andaorta wall portion 34 (see FIG. 22). This provides a completedanastomosis of the proximal end of conduit 530 to aorta 30.

The next step is to deflate balloons 512 a and 512 b and proximallywithdraw tube 510 and delivery tube 540 from the patient via catheter210. Then wire 150 is withdrawn from the patient, either by pulling itproximally from catheter 210 or by pulling it proximally from elements110 and 120. Lastly, elements 110, 120, and 210 are all proximallywithdrawn from the patient to conclude the procedure. The bypass that isleft in the patient is as shown in FIG. 23. This bypass extends fromaorta 30 at location 34 to coronary artery 20 at location 24. The bypassincludes natural body conduit 530 inside artificial graft conduit 430.One end of the bypass is anchored and anastomosed to coronary artery 20by prongs 436 and ring 520 a. The other end of the bypass is anchoredand anastomosed to aorta 30 by flaps 438 and ring 520 b.

The particular uses of the invention that have been described in detailabove are only illustrative of many possible uses of the invention.Other examples include same-vessel bypasses in the coronary area andvessel-to-vessel and same-vessel bypasses in other portions of thecirculatory system (including neurological areas, renal areas,urological areas, gynecological areas, and peripheral areas generally).A same-vessel bypass is a bypass that extends from one portion of avessel to another axially spaced portion of the same vessel. In FIG. 24,bypass 620 is a same-vessel bypass around a narrowing 612 in vessel 610.For ease of comparison to previously described embodiments, the variouscomponents of bypass 620 are identified using the same reference numbersthat are used for similar elements in FIG. 23. The invention is alsoapplicable to procedures similar to any of those mentioned above, butfor non-circulatory systems such as urological tubing.

Another illustrative alternative embodiment of some of theinstrumentation shown in FIG. 7 is shown in FIGS. 25 and 26. Tofacilitate comparison to FIG. 7, FIGS. 25 and 26 use reference numberswith primes for elements that are generally similar to elementsidentified by the corresponding unprimed reference numbers in FIG. 7.Each axial end portion of graft 430 includes a radially enlargeableconnector structure 449. Connector structures 449 may have any of alarge number of constructions. For example, each connector structure 449may include one or more annularly compressible, serpentine-shaped, metalrings 448 (e.g., of nitinol). When such a ring is annularly compressed,the serpentine convolutions of the ring become more sharply curved andcloser together. When such a ring is released to return to a more nearlyrelaxed state, the convolutions of the ring become somewhat straighter.If graft 450 is made of a metal (e.g., nitinol) framework 432 with acovering 434 (e.g., of silicone), rings 448 may be integral withframework 432, and covering 434 may continue into the vicinity of rings448. Rings 448 may be formed to hold struts 436′ substantially uniformlyout against the inner surface of body tubing all the way around thecircumference of the graft.

A particularly preferred way of producing a serpentine ring 448 is tostart with a short length of thin-walled metal tubing 460 as shown inFIG. 28 and cut away interdigitated portions 462 from opposite axialends of the tube as shown in FIG. 29. A typical thickness of tubing 460is approximately 0.003 to 0.006 inches, and a typical width of metalleft between adjacent slots 462 is about 0.008 inches. Slots 462 may becut in tubing 460 using a laser. The structure shown in FIG. 29 is thenradially enlarged and annealed. In its radially enlarged form, thestructure has the general appearance shown in FIG. 27 when viewed froman axial end. Each point 458 is adjacent an axial end of the originaltube 460. The structure can be resiliently radially compressed to thesize of the original tube 460 or an even smaller size, and it willreturn to the radially enlarged size and shape whenever released fromradial compression. Points 458 form radially outwardly extending highspots or raised portions that help ring 448 securely engage surroundingbody tissue by locally projecting to a greater extent into the tissue,even though points 458 may not actually penetrate the tissue.

As an alternative or addition to reliance on a ring like 448 toresiliently (elastically) self-expand to the full circumferential sizedesired in a completed graft connection, some or all of the desiredcircumferential expansion of such a ring may be produced by inflatingballoon 422′ or using another selectively radially enlargeable structureinside the ring to plastically deform the ring.

For use in a connector structure that includes struts like 436′, eachstrut may be connected (e.g., welded) to a peak of the serpentinestructure as shown for example in FIG. 29 a. This may be done at anyconvenient time (e.g., before circumferential expansion of the FIG. 29structure).

It will be noted that a ring 448 made as described above in connectionwith FIGS. 27-29 a may be somewhat ribbon-like (e.g., because the widthof the metal between slots 462 is greater than the thickness of thatmetal). Thus when the structure shown in FIG. 29 or 29 a iscircumferentially enlarged, the material in the peaks 458 of theconvolutions tends to twist. This can give these peaks a shape which isespecially effective in engaging adjacent body tissue. If struts like436′ are attached to these peaks as shown in FIG. 29 a, the twisting ofthe peak material can be used to similarly twist the struts (e.g., tobias them in favor of radial outward projection and/or to rotate themabout their longitudinal axes to properly orient hooks and/or barbs onthem).

In the embodiment shown in FIGS. 25 and 26 struts 436′ are connected tothe distal end of the serpentine ring 448 of the connector 449, which isconnected in turn to the distal end of frame 432′. Struts 436′ areinitially held in the form of a distally pointed cone by yieldable bands437 a, 437 b, 437 c, and 437 d. As elsewhere along graft conduit 430′,the spaces between struts 436′ are substantially filled by a highlyelastic material such as silicone rubber. Bands 437 may be made of apolymeric or other suitable yieldable material. Alternatively, bands 437could be serpentine metal members that yield by becoming straighter.Bands 437 are initially strong enough to prevent struts 436′ fromflaring radially outward from conduit 430′ as the struts are resilientlybiased to do. However, bands 437 can be made to yield by inflatingballoon 422′ (on the distal end of tube 420′) inside the annulus ofstruts 436′.

Struts 436′ can be forced through tissue such as the wall of coronaryartery 20 in their initial cone shape. Sufficient pushing force can beapplied to the cone of struts 436′ in any of several ways. For example,tube 420′ may be metal (e.g., stainless steel) hypotube which cantransmit pushing force to the cone of struts 436′ by inflating balloon422′ to trap the base of the cone between balloon 422′ and tube 440.Additional pushing force may then also be applied via tube 440 itself.

When a sufficient portion of the height of the cone of struts 436′ isthrough the coronary artery wall, balloon 422′ is inflated inside thecone as shown in FIG. 26 to cause bands 437 to yield. This allows struts436′ to flare radially outward inside the coronary artery, therebyanchoring the distal end of conduit 430′ to the artery. Bands 437 may bemade progressively weaker in the distal direction to facilitate promptyielding of distal bands such as 437 a and 437 b in response torelatively little inflation of balloon 422′, whereas more proximal bandssuch as 437 c and 437 d do not yield until somewhat later in response togreater inflation of balloon 422′. This progression of yielding may helpensure that the annulus of barbs flares out in the desired trumpet-bellshape inside the coronary artery.

As shown in FIG. 26 a, in another embodiment struts 436′ are initiallyheld in the form of a distally pointed cone by a yieldable cone 441which is attached to or is part of tube 440. Cone 441 may be made of apolymeric or other suitable yieldable material. Cone 441 is initiallystrong enough to prevent struts 436′ from flaring radially outward fromconduit 430′ as the struts 436′ are resiliently biased to do. However,cone 441 can be made to yield by inflating balloon 422′ (on the distalend of tube 420′) inside the annulus of struts 436′. Struts 436′ can beforced through tissue such as the wall of coronary artery 20 in theirinitial cone shape. Sufficient pushing force can be applied to the coneof struts 436′ in any of several ways. For example, tube 420′ may bemetal (e.g., stainless steel) hypotube which can transmit pushing forceto the cone of struts 436′ by inflating balloon 422′ to trap the base ofthe cone between balloon 422′ and tube 440. Additional pushing force maythen also be applied via tube 440 itself.

When a sufficient portion of the height of the cone of struts 436′ isthrough the coronary artery wall, balloon 422′ is inflated inside thecone as shown in FIG. 26 a to cause cone 441 to yield. This allowsstruts 436′ to flare radially outward inside the coronary artery,thereby anchoring the distal end of conduit 430′ to the artery. Cone 441may be made progressively weaker in the distal direction to facilitateprompt yielding of distal end in response to relatively little inflationof balloon 422′, whereas the more proximal end does not yield untilsomewhat later in response to greater inflation of balloon 422′. Thisprogression of yielding may help ensure that the annulus of struts 436′flares out in the desired trumpet-bell shape inside the coronary artery.The cone 441 may be withdrawn with the tube 440, and may even be madepart of tube 440.

FIG. 26 b depicts tube 440 and cone 441 by themselves in order to bettershow that cone 441 may have a weakened zone 441 a extending in thedistal direction to help the cone yield to deploy struts 436′ whenballoon 422′ is inflated. Weakened zone 441 a can be a slit, a scoreline, a perforation line or any other generally similar structuralfeature.

Still another illustrative alternative embodiment of some of theinstrumentation shown in FIG. 7 is shown in FIG. 30. To facilitatecomparison to FIG. 7, FIG. 30 uses reference numbers with double primesfor elements that are generally similar to elements identified by thecorresponding unprimed reference numbers in FIG. 7. In the embodimentshown in FIG. 30, the distal end of artificial graft conduit 430″ isattached to expandable ring 448. Elongated struts 436″ extend distallyfrom the distal end of ring 448. The distal ends of struts 436″ areturned back in the proximal direction and extend just far enough intothe distal end of tube 420″ to be releasably retained by that tube.Struts 436″ are resiliently biased to extend radially outward from ring448, but are initially restrained from doing so by the presence of theirdistal end portions in the distal end of tube 420″. Thus struts 436″initially form a distally pointing cone that can be pushed throughtissue such as the wall of coronary artery 20 in the same manner thathas been described above in connection with FIGS. 25 and 26. Structure420″, which may be metal (e.g., stainless steel) hypotube with aninflatable annular balloon 422″ near its distal end, may be used to helppush the cone through the tissue.

After the distal portion of the cone of struts 436″ has been pushedthrough the wall of coronary artery 20, tube 420″ is shifted proximallyrelative to the struts 436″ to release the distal end portions of thebarbs. This allows struts 436″ to spring radially outward from ring 448inside coronary artery 20, thereby anchoring the distal end of the graftconduit in the coronary artery. Ring 448 can then be circumferentiallyexpanded to increase the size of the connection between coronary artery20 and the distal portion of the graft conduit. If desired, each ofstruts 436″ may be twisted 180° before it enters the distal end of tube420″. This promotes turning of the hook-like extreme distal end portionsof the struts toward the coronary artery wall when the struts arereleased from tube 420″.

Ring 448 and struts 436″ may be made of any suitable material such asany 300-series stainless steel (e.g., 316L stainless steel). Anothermaterial that may be suitable for struts 436″ is nitinol. As inpreviously described embodiments, the elastic cover 434 that forms partof conduit 430″ preferably extends to regions 430 a and 436″.

In FIG. 30, the struts 436″ are attached to ring 448 at the closest(distal-most) points of the ring 448. This causes the struts 436″ topull in the proximal direction when the ring 448 is expanded by balloon422″. This causes the hooks on the ends of the struts to pull into thesurrounding tissue for a more secure attachment. The hooks on the endsof struts 436″ may also have barbs formed thereon for an even moresecure attachment to body tissue.

As shown in FIG. 30 a, there may also be outer struts 435 which areattached to the farthest (proximal-most) points of the ring 448 and to aband 433 at their distal ends. When the ring 448 expands, the outerstruts 435 are pushed in the distal direction, which causes band 433 tomove distally, and therefore closer to the artery wall to help sealagainst the artery wall. In other words, the body tissue is trappedbetween radially outwardly extending struts 436″ on the inside of thetissue wall and band 433 on the outside of the tissue wall.Circumferential expansion of ring 448 and consequent proximal motion ofbarbs 436″ and distal motion of band 433 apply compressive stress to thetissue wall between those inner and outer portions of the connector.

Still another illustrative alternative embodiment of some of theinstrumentation shown in FIG. 7 is shown in FIG. 31. In the embodimentshown in FIG. 31, the distal end of artificial graft conduit 430 isattached to expandable ring 448. Elongated struts 436 extend distallyfrom the distal end of ring 448. The distal ends of struts 436 havehooks 466 having small barbs 467 at the ends. The struts 436 are turnedback in the proximal direction. Struts 436 are resiliently biased toextend radially outward from ring 448, but they are initially restrainedfrom doing so by the presence of their distal end portions wrapped by arestraining wire 465. Thus struts 436 initially form a distally pointingcone that can be pushed through tissue such as the wall of coronaryartery 20 in the same manner that has been described above. The wire465, which may be metal (e.g., stainless steel), is then pulled backproximally to unwrap the distal portion from around the struts. Thisallows struts 436 to spring radially outwardly from ring 448 insidecoronary artery 20, thereby anchoring the distal end of the graftconduit in the coronary artery using the hooks 466 and barbs 467. Ring448 can be circumferentially expanded at any suitable time to increasethe size of the connection between coronary artery 20 and the distalportion of the graft conduit 430.

FIG. 32 shows a variation of the FIG. 31 apparatus. In the FIG. 32variation, struts 436″ are initially restrained by a loop or coil on thedistal end of wire 465″. Wire 465″ extends distally from a lumen in thewall of tube 420. When it is desired to release struts 436″ to extendradially outwardly, tube 420 is rotated about its central longitudinalaxis. This rotates the loop or coil in wire 465″, thereby releasingstruts 436″ one after another. After all of struts 436″ have beenreleased from the wire loop, wire 465″ may be proximally retractedrelative to tube 420 so that the loop in wire 465″ is adjacent thedistal end of that tube. Alternatively, wire 465″ may be proximallyretracted all the way into the lumen in the wall of tube 420 from whichthe wire initially extends.

An alternative construction of the proximal end of artificial graftconduit 430 is shown in FIG. 33. The embodiment shown in FIG. 33 can beused with any construction of the distal end of conduit 430, but FIG. 33assumes that the depicted proximal end construction is used with adistal end construction of any of the types shown in FIGS. 25-26 a and30-32.

In the embodiment shown in FIG. 33 the proximal end of conduit 430 has aplurality of struts 1436 that are resiliently biased to extend radiallyout from the remainder of the conduit. Initially, however, struts 1436are confined within delivery tube 440 as shown in FIG. 33. Like distalstruts 436, struts 1436 may be proximal extensions of the frame 432 ofconduit 430, or they may extend proximally from a ring at or near theproximal end of conduit 430. This proximal ring may be similar to distalring 448 described above in connection with FIGS. like FIG. 25. Thecovering 434 of conduit 430 may extend to all, part, or none of thelength of struts 1436. Struts 1436 may include resilient hooks, and thefree end portions of struts 1436 or the hooks on those struts mayinclude barbs. Representative struts 1436, each with a hook 1466 and abarb 1467, are shown after deployment and in more detail in FIG. 34.This FIG. shows that struts 1436 flare out inside aorta 30 and that thefree ends of hooks 1466 penetrate the aorta wall tissue shown at 34.Barbs 1467 engage the tissue like fish hook barbs to resist any tendencyof hooks 1466 to pull out of the tissue.

The proximal end of conduit 430 is attached to the wall of aorta 30(after attachment of the distal end to coronary artery 20 as describedabove in connection with numerous other FIGS.) by proximally retractingdelivery tube 440 so that struts 1436 can spring out against the insideof catheter 210 in the vicinity of proximal balloon 212. Then distalballoon 214 is deflated and catheter 210 is retracted proximally so thatstruts 1436 can spring out against the inside surface of the wall ofaorta 30 as is generally shown in FIG. 34. If provided, hooks 1466 andbarbs 1467 penetrate the aorta tissue as shown in FIG. 34.

As part of the procedure for connecting the proximal end of conduit 430to the aorta, it may be desirable to proximally retract the balloon422/422′/422″ (described above in connection with numerous other FIGS.)to the proximal end of conduit 430 and to there re-inflate the balloonto help hold conduit 430 in place before proximally retracting deliverytube 440. The balloon can be deflated again at any suitable time (e.g.,after delivery tube 440 has been proximally retracted). Balloon422/422′/422″ may additionally or alternatively be inflated duringproximal retraction of catheter 210. This may help ensure that struts1436 are fully and properly deployed and that the connection of conduit430 to aorta 30 is properly molded. If a ring similar to ring 448 ispart of the proximal conduit connection, inflation of balloon422/422′/422″ may be used to circumferentially expand that ring as partof the process of connecting conduit 430 to the aorta.

Possible refinements of a proximal connector of the general type shownin FIGS. 33 and 34 are shown in FIGS. 34 a and 34 b. (The structureshown in FIGS. 34 a and 34 b can also be used as a distal connector.)FIGS. 34 a and 34 b show the connector fully installed though anaperture in body tissue wall 34. Artificial graft conduit 430 is formedso that its proximal portion is resiliently biased to assume the shapeshown in FIGS. 34 a and 34 b. In particular, this shape includes amedial, radially outwardly projecting, annular flange 430 a, and aproximal, radially outwardly projecting, annular flap 430 b. Flange 430a is intended to be deployed outside body tissue wall 34 as shown inFIG. 34 a, while flap 34 b is intended to be deployed inside the bodytissue wall. In addition, a connector 449 (similar to the connectors 449in earlier-described FIGS. such as FIGS. 25-30, 31, and 32) is providedadjacent flap 430 b. Connector 449 includes a radially expandableserpentine ring 448 and a plurality of struts 436 which are resilientlybiased to project radially outwardly. In this embodiment struts 436 passthrough the structure of flap 430 b to help push the flap up inside andagainst the inner surface of tissue wall 34.

As in previous embodiments, the structure shown in FIGS. 34 a and 34 bmay be delivered to the intended location in the body inside a deliverytube (e.g., like tube 440 in FIG. 33). While the structure is inside thedelivery tube, all of elements 430 a, 430 b, and 436 are constrained bythat tube into a substantially tubular shape. When the delivery tube isproximally retracted from conduit 430, elements 430 a, 430 b, and 436resiliently return to the shapes shown in FIGS. 34 a and 34 b, therebymaking a secure and fluid-tight connection between the proximal end ofconduit 430 and body tissue wall 34.

FIG. 35 illustrates another possible use of the connecting structures asdescribed above, as well as illustrating other possible aspects of theinvention. FIG. 35 illustrates a structure that can be used to deliveran artificial graft conduit, or a natural graft conduit, or both anartificial graft conduit and a natural graft conduit simultaneously(e.g., with the natural conduit coaxially inside the artificialconduit). In the particular case shown in FIG. 35 it is assumed thatonly natural graft conduit is being delivered, but it will be readilyapparent that artificial graft conduit could be substituted for or addedoutside the natural graft conduit.

In the embodiment shown in FIG. 35 the cone of struts 436′ is attachedto the distal end of a natural graft conduit 530. The proximal end ofnatural graft conduit 530 is attached to ring 461. The cone of struts436′ is provided with relatively short, radially outwardly projectingprongs 433. Prongs 433 extend into and/or through the distal portion ofthe length of graft tubing 530, which (as has been mentioned) is assumedin this case to be natural body organ tubing such as saphenous vein.Ring 461 is similarly provided with radially outwardly extending prongs462, which extend into and/or through the proximal portion of graftconduit 530. Ring 461 also includes resilient radially outwardlyextending annular flaps 438 a and 438 b with prongs 439, all similar tocorrespondingly numbered elements in FIG. 8. Structure 420′ is disposedaround wire 150 inside structures 436′, 450, 460, and 530. Delivery tube440 is disposed around conduit 530.

The embodiment shown in FIG. 35 illustrates a structure which can beused to deliver and install natural body organ conduit without any fulllength artificial graft conduit being used. In a manner similar to whatis shown in the previous FIGS., the structure shown in FIG. 35 isdelivered to the operative site via wire 150. The cone of struts 436′ isforced through the wall of coronary artery 20 and then flared radiallyoutward inside the coronary artery to anchor the distal end of the graftconduit to that artery. The distal end of delivery tube 440 is pulledback as needed to aid in attachment of the distal end of the graftstructure. Attachment of the proximal end of the graft structure to thewall of aorta 30 is performed similarly to what is shown in the aboveFIGS. Accordingly, with distal flap 438 a just outside the wall of aorta30, delivery tube 440 is pulled back proximally to expose that flap.Flap 438 a is thereby released to spring out and engage the outersurface of the aorta wall. After that has occurred, proximal flap 438 bis adjacent the inner surface of the aorta wall. Tube 440 is pulled backproximally even farther to expose flap 438 b so that it can spring outand engage the inner surface of the aorta wall. Natural body organ graft530 is now fully installed in the patient. Struts 436′, 450, and 460remain in place in the patient to help anchor the ends of graft conduit530 and to help hold open the medial portion of that conduit.

FIG. 36 shows an alternative to what is shown in FIG. 35. In FIG. 36 adistal annular connector structure 449 a is annularly attached to thedistal end of conduit 530 (similar to conduit 530 in FIG. 35), and aproximal annular connector structure 449 b is annularly attached to theproximal end of conduit 530. For example, each of connectors 449 may besutured to the respective end of conduit 530. In that case connectors449 may be inside or outside conduit 530. Each of connectors 449 may besimilar to the connectors 449 in earlier-described FIGS. such as FIGS.25-30, 31, and 32. Thus, each of connectors 449 includes a serpentinering 448 with a plurality of struts 436 extending from the ring. Withthis construction, as an addition or alternative to suturing eachconnector 449 to conduit 530, the ring 448 of each connector may beinside the conduit and the high spots 458 (FIG. 27) on the ring may beused to dig into the tissue of conduit 530 (without actually penetratingthe tissue) to secure or help secure the connector to the tissue.

The struts 436 a of distal connector 449 a extend in the distaldirection from ring 448 a and are initially restrained into a cone shapeby a release wire 465 as shown in FIG. 31. The struts 436 b of proximalconnector 449 b extend in the proximal direction from ring 448 b and areinitially constrained by being inside delivery tube 440. The struts 436a of distal connector 448 a are deployed to spring radially outwardlyand engage body tissue by proximally retracting release wire 465. Thestruts 436 b of proximal connector 448 b are deployed to spring radiallyoutwardly and engage body tissue by proximally retracting delivery tube440. The structure shown in FIG. 36 can be used in any of the ways thatare described above for the structure shown in FIG. 35.

FIG. 37 shows a structure that may be used as an alternative to theembodiments described above. For example, structures like this may beused in place of the connectors using barbs, or wherever else agenerally similar connecting structure is needed. A T-flange connector700 is provided. It is constructed generally similar to the graftconduits 430 described above, having a frame, and a covering. Theconnector 700 is formed in the shape of a “T” of hollow tubular sectionsand is resiliently biased to return to this shape. The connector isinitially deployed with one of the ends 702 of the top of the “T”inverted or compressed into the other end 704 of the top of the “T” asshown in FIG. 38. The compressed connector is then deployed using a tube440 as described above. Once the tube 440 is withdrawn, the connector700 expands to its original “T” shape. For example, the top of the “T”may be inserted into coronary artery 20 through an aperture in the sidewall of that artery as shown in FIG. 39. After insertion, one leg 704 ofthe top of the “T” extends upstream along the coronary artery, and theother leg 702 extends downstream along that artery as shown in FIG. 40.The remainder of the “T” (i.e., the “vertical” portion of the “T”)extends out of the aperture in the coronary artery so that the base ofthe “T” can be connected to the aorta (e.g., using any of the otherconnector structures and techniques described above). The fact that thetop of the “T” extends both upstream and downstream along the coronaryartery anchors the graft to the coronary artery.

As used herein, references to a patient's existing body organ tubing orthe like include both natural and previously installed graft tubing(whether natural, artificial, or both). The artificial grafts of thisinvention may be coated (in the case of tubular grafts, on the insideand/or outside) to still further enhance their bio-utility. Examples ofsuitable coatings are medicated coatings, hydrophylic coatings,smoothing coatings, collagen coatings, human cell seeding coatings, etc.The above-described preferred porosity of the graft covering helps thegraft to retain these coatings. Additional advantages of the artificialgrafts of this invention are their elasticity and distensibility, theirability to be deployed through tubes of smaller diameter (after whichthey automatically return to their full diameter), the possibility ofmaking them modular, their ability to accept natural body organ tubingconcentrically inside themselves, their ability to support developmentof an endothelial layer, their compatibility with MRI procedures, theirability to be made fluoroscopically visible, etc.

It will be understood that the foregoing is only illustrative of theprinciples of the invention, and that various modifications can be madeby those skilled in the art without departing from the scope and spiritof the invention. For example, the order of some steps in the proceduresthat have been described are not critical and can be changed if desired.

1. A connector for use in connecting an axial end portion of a tubularmedical graft to the side wall of a patient's tubular body tissueconduit so that the lumen of the graft communicates with the lumen ofthe conduit through an aperture in the side wall of the conduit topermit body fluid flow between the lumens without leakage of body fluidto the outside of the graft and the conduit adjacent the connectorcomprising: an annular structure having first and second axiallyadjacent substructures, the first substructure being configured to bedisposed substantially concentrically inside the axial end portion ofthe graft and being circumferentially enlargeable to press the axial endportion of the graft radially outwardly toward the body tissuesurrounding the aperture, and the second substructure including aplurality of struts that are configured to extend from a first positionin which the struts are substantially longitudinal to an axis aboutwhich the annular structure is substantially coaxial to a secondposition in which the struts are radially outward and substantiallyperpendicular to the axis to engage the body tissue surrounding theaperture and hold the axial end portion of the graft in body-fluid-tightengagement with the side wall of the conduit annularly around theaperture, wherein the first substructure is resiliently biased tocircumferentially enlarge to at least some degree by itself and whereinthe struts are resiliently biased to extend from the first position tothe second position, and wherein the struts form a cone which has itsapex on an axis about which the annular structure is substantiallycoaxial when in the first position; and a removable member around thestruts, wherein the removable member comprises a wire wrapped around thestruts, the wire having an end portion adapted to be actuated to unwrapthe wire from around the struts.
 2. A connector for use in connecting anaxial end portion of a tubular medical graft to the side wall of apatient's tubular body tissue conduit so that the lumen of the graftcommunicates with the lumen of the conduit through an aperture in theside wall of the conduit to permit body fluid flow between the lumenswithout leakage of body fluid to the outside of the graft and theconduit adjacent the connector comprising: an annular structure havingfirst and second axially adjacent substructures, the first substructurebeing configured to be disposed substantially concentrically inside theaxial end portion of the graft and being circumferentially enlargeableto press the axial end portion of the graft radially outwardly towardthe body tissue surrounding the aperture, and the second substructureincluding a plurality of struts that are configured to extend from afirst position in which the struts are substantially longitudinal to anaxis about which the annular structure is substantially coaxial to asecond position in which the struts are radially outward andsubstantially perpendicular to the axis to engage the body tissuesurrounding the aperture and hold the axial end portion of the graft inbody-fluid-tight engagement with the side wall of the conduit annularlyaround the aperture, wherein the first substructure is resilientlybiased to circumferentially enlarge to at least some degree by itselfand wherein the struts are resiliently biased to extend from the firstposition to the second position, and wherein the struts form a conewhich has its apex on an axis about which the annular structure issubstantially coaxial when in the first position; and a removable memberaround the struts, wherein the removable member comprises a coil aroundthe struts configured to release the struts when the coil is rotatedabout its central longitudinal axis.
 3. The connector defined in claim1, wherein the end portion is adapted to be pulled to unwrap the wirefrom around the struts.
 4. The connector defined in claim 1, wherein theend portion extends substantially along the axis about which the annularstructure is substantially coaxial.